Automatic control for refrigerating machines



June 16, 1925.

1,542,479 c. SCHWEINLE AUTOMATIC CONTROL FOR REFRIGERATING MACHINESFiled May 29, 1924 2 Sheets-Sheet amw June 16, 1925 1,542,479

C. SCHWEINLE AUTOMATIC CONTROL FOR REFRIGERATING MACHINES Filed May 29,1924 2 Sheets-Sheet FIG. 3

. a citizen'ofthe United States Milwaukee and automatically Figure 3 isa Patented June 16, 1925. I

UNITED STATE s PATENT OFFICE.

scnwmnm; or mrnwsminn, Wisconsin, nssxonoa' T0 anrnreo coawrsconsm, Aoonronsrron OF WISCONSIN.

nu'roziurlccon'rnon roe nnrmom'rme macnm'as.

Application filed May 29,- 19?A. Serial N'o. 716,811,

To all whom it may concern:

Be it known that 1, CHARLES Sonwnmne, of America, residing at Milwaukee,in the county of State of \Visconsin, have invented certain new anduseful Improvements in Automatic Controls for Refrigerating Machines, ofwhich .the following is a specification. v

This invention relates to new and useful improvements in automaticcontrols for refrigerating machines and sets fortha device which isespecially adapted for controlling the operation of electric motorsemployed for driving compressors. I

An important object of the; invention is to provide a control for acompressor moton which is primarily governed by the te'ni perature inthe spaces being cooled by the refrigerating plant:

A further object of the invention is to provide an auxiliary control for-'the compressor motor which is governed by the pressure of water beingfed to the compressor whereby the compressor motor will be shut off whenthe water pres sure drops below, a predetermined-point. H

, A still further object of the invention is.

togprovide means,

controlled by tempera- "ture, for governing the supply of water-to acompressor, and means, controlled by the pressure of the water beingsupplied to a compressor, for governing the operation of A the stem isprovided with the motor driving said compressor,

Another object of the invention is to provide temperature governedelectrical means for controlling the supply of water to a compressor. sf, 1

Other objects and advantages of the in vention will be apparent duringthe course of the following description.

In the accompanying drawings forming a part of this specification'and inwhich like numerals are employed to, designate like parts throughout thesame, I Figure 1 illustrates a front elevationalv view of theapparatus-embodying this in vention, I V Figure 2 illustrates a verticalsectional view taken upon lines lI-- l I'of'E ig. 1,

diagrammatical View of the connection or wiring system for L electricalthe apparatus illustrated in Fig. '1, and

' pressor, not

; 4 ne The coup as at 26, and is Figure 4 is a detail side elevationalview of a portion of the structure illustrated in Fig. 1.

In the drawings, of illustration is shown a preferred embodiment of thisinvention, the numeral 5 designates a water supply pipewhich isintendedwherein for the purpose to be connected to a suitable water main, I orthe like, and has connectedthereto a substantially T-shaped coupler 6.Thiscounler 6 has conIiected to its branch 7 a p e 8 which is connectedat its outer on to a union 9 having a second nipple 10 leading therefromto the coupler 11. "This'coupler i has connected to the branch; 124{nipple ,13 which is joined with a valve casing i'ng a pipe 15 leadingtherefrom to a cor'n' shown,

' The T-coupler'6 is provided with a partition 16, extendingtransversely therethrough, having a valve 'seat 17 formed therein. ,Thiscouplexfidsi iurther provided with a flange end 18 'to 'which isconnected a leak preventing"diaphragm isw and the flange 200i anextens1on21 which is pro vided with a centrally apertured cap nut 22.Reciprocally. mounted within the extension 21 and the coupler 6 is avalve-stem 23' which projects outwardly through, the -aperture formed inthe cap'nut 22 This stem 23 is suitably connected $0 thepleak preventingdiaphragm 19, as at 19", for preventing any lea age around'this stem."The lower end of a valve 2/1 which is adapted to enga ev the seat 17for shutting o the flow 0 water from the pipe 5 to, the nipple 8, thewater pressure 111 the ,5: normally acting to retain the seatlflr- I ler11 is provided with a jflanged branch 25 that is adapted tohaveconnected thereto a diaphragrn flfi and a flange 27 carried bythetubularextension 28. This exthe; valve tension is'provided' with acentrally apertured cap nut 29," within-which "is reciprocally mountedtheT-stem 30.: This stem 30 is suitably. connected to the diaphragm 26,

sion sprin'gBl w ich engages, atits lower rovided with a compre's-- end,the structure employed for connecting the stem 30 to the diaphra m 26,and further engages, at its upper ,en a shoulder 32 formed in theextension .28. It will be,

seen that this compression spring 31 normally operates for forcingdownwardly upon the stem 31 and the diaphragm The valve casing ll isprovided with a rotatable valve element 33 which is operated by the head34 and is employed for positively shutting off the flow of water to thepipe and the compressor. not shown.

Suitably connected to the extensions 21 and 28, as by' the anglebrackets is a metallic box 36 which is provided with a hinged door 37for closing the tront iof the same. Mounted within this box is a base38, formed of slate or other insulating inat'erial, which is heldtherein by the bolts 39 'having the spacers l0 and the nuts 41.

Suitably secured to this base 38 is a magnet frame including the backportion 42 and the bracket arms 43 and 44. Connected to these arms 43and 44 is a brass tube 45 which has wound therearound a magnetic coil46, the tube 4:5 and coil 46 forming a solenoid. Loosely. mounted withinthe brass tube 45 is a core 47 which is provided with a stem lS-thatprojects outwardly of the upper end of the the tube 45 and also cxtendsthrough a suitable aperture formed in the arm 44 for the purpose ofcarrying a block 49 above this arm 44, the block 49 having a notch 50formed therein. The upper portion of the back 42 of the magnet frame hassecured thereto a solid core 51 which has wound therearound a magneticcoil 52.

Suitably secured to the arm 44 of the magnetic frame is a. doublebearing element which employed for rotatably supporting the rod This rodhas mounted thereon a pawl 55 which is normally retained in a forwardlyllh'liHGCl position, against the block 49. by a weight 56 which iscarried by .an arm 57 rigidly mounted upon the rod 54. it being againnoted that this weight 56 will retain the pawl 55 in engagement with theblock 4-9 carried by the solenoid core stem -18 whereby movement of theblock upwardly will cause the pawl 55 to engage the notch 50 formed inthis block 49 for retaining the core 47 in an elevated position. It,also. will be noted that the pawl 55 is so arranged in respect to thesolid core 51 that when the magnetic coil is energized, the pawl will beattracted and moved into engagc'nmt with the outer end of the solid core51.

Pivotally connected. as by the bearings 58, to one side of the metallicbox 36 is a lever 59 which projects into the box, through the opening()0 and has its end (31 normally bearing against the upper end of theblock 49 carried by the stem 18. The outer end 62 of the lever 59 isadjustably connected to the upper end of the valve stem 23, as by thenut (13 threaded upon said stem. and is so formed that the upper end oithe stem 23 means will be permitted to more laterally of the end 62 ofthe lever 59. In other words, the end 82 is provided with a verticallyextending opening 62 which is of greater diam etcr than the stem 23 and.permits a desired amount of play of the latter therein.

Suitably connected to the insulating base 38, as by the bolts 64 is areversely bent bracket (35 that is adapted for carrying the adjustablecontact post (36, as best illustrated in Fig. :2. The end of the rod 54opposite to the weight 56, is provided with a sleeve (57, formed ofinsulating material, upon which is positioned the clamp 68 which is inthe form of astrap bent upon itself and.

adjustei'l by means of the bolt 69. This clamp 8 is adapted for carryinga switch switch blade 70 will be spaced from the contact end of the post66. It will be understood that when the block is positioned below theposition illustrated in Fig. 2, that is without the pawl 55 receivedwithin the notch 50, the normal diameter of the block 5!) will retainthe pawl 55 substantially in engagement with the outer end of the solidcore 51 and the lower end of the switch blade 70 will engage thecomactpost 66.

A three-pole switch is mounted u on the insulating base 38 and consistsof tie elongated insulating block 755 which is secured to the base bythe bolts 73 and positioned outwardly therefrom by the tubular spacers74., This elongated block '72 has secured thereto, as by the bindingscrews 74:, three spaced, substantially L-shaped metallic contacts 75which have their feet portion 75 flushly engaging tbe lower longitudinalface of the said block.

Journaled in the bearing brackets 76, arried by opposite longitudinaledges of the insulating base 38, is a rotatable rod 79 which is covered,between the bearing brackets 76, by an insulating sleeve 80. Adjustablysecured to these elements 79 and 80 are the clamps 81, which are in theform of straps bent upon themselves and retained. in. position by thescrews 82. Each clamp is provided with a projecting arm 81 which carriesa screw 83 having a tension spring. 84- surroundmg the sameand held inplace by a washer Connected to the arm 81 of each clamp 81' is a blade86 having a brush 87 mounted upon its outer end. This brush 87 providedwith a suitable aperture which receives the scr w R25 and is permittedto move relatively thereto, the spring 8-l normally tending to hold theintcrn'iediare portion of the blade 86 in flush engageis screw threaded,as at-93, for receiving to one lead of the solenoid coil 46 by avidedwith a bifurcated end 92 that loosely receives the stem 30connected to the diaphragm 26. The outer end of this stem the adjustablenut 94, as illustratedf This stem 30 is further provided with a washer95, which is held in position by the in 96,

passing through the stem 30, and y the;

o f a wire 111. The bindingscrew .64, 61cccompression spring 97 whichbears thereagainst'at its lower end and against the bifurcated end 92 ofthe arm 91, at its upper end.

. In Fig. 1, the wiring system is illustrated as being properlyconnected to the various elements previously described while in Fig. 3this wiring system is illustrated diagrammatically for'better enabling aperson to trace the same. Three main feed lines, A, B, and G, areillustrated as being connected to the respective contact plates 88, bymeans of the binding screws 89. Each one of the screws 83, carried bythe arms 81 of the clamps 81, is connected to one of the con.- tactplates 88, by a. pigtail 99. The contact plates 75 have connectedthereto, as by means of the binding screws 74, feed lines w, '-bandwhich are intended to lead to a motor, not shown, which is employed fordriving a compressor, not shown. It will be noted that the motor feedwire. -a and the line wireA are intendcd to be connected by one of theswitch blades 86, while the motor feed wires .band care intended to beconnected to the main line wires B and C respectively by theremaining'two switch blades 86. It might be well to note at this thisthree-wire system is inten ed to be employed for a three-phase motor andit is to be understood that the motor feed wire and the main feed lineB, with their reacting switch elements and bindi posts,

. may be eliminated it the compressor is driven by a single phase motor.

l'n Fig. 3 there is shown a thermostatic unit. designated in itsentirety by the numeral, 100, and this thermostatic'unit consists of athermostatic bar 101 which is connected by a wire 102 toa binding post103 carried by the insulator base 38. The contact 104, associated withthe thermostatic bar 1.01, is connected by a wire 105 to a bindingpost106, carried by the insulator base oint that y 38 while the secondcontact bar 107 is connected by a wire 108 with a binding post 109,carried by theinsulator base 38. It is to be understood that'thisthermostatic bar 101 is formed of a suitable substance or material forcausing the same to be influenced by a'change in temperature and thatsuch changes will cause the bar to flex for engaging the differentcontact elements 104. and 107 for closing the circuit from the wire 102to either of the wires 105 or 108. It isto be understood thatthisthermostatic unit 100 is to be positioned within the space intended tobecooled by the refrigerating system controlled by this apparatus.

The binding post 106 is to be connected trically connected to thexcontact 66 by the bracket 65, is intended to nected to the contactplate 88,. associated with the main feed line C, by the wire 112. Thebinding post 109 is to beconnected to one lead of the coil 52 by meansof the wire 113 while the remaining lead of the coil is to" beconnected-to the binding screw 74;, associated with the motor feed liner-. by means of the wire"114. The remaining binding post 103 is to bedirectly connected to the contact plate'88, i'nse'ries with'the mainfeed line A, by meansof the wire 11.5. It is now believed that thewiring system has been clearly described and a person skilled in the artwill be able to trace the same without any diificulty.

The operation of the apparatus embodying this invention is as follows tThe apparatus will first be considered with all of the elements arrangedasjjilluse tinted in Figs. 1. to 3 inclusive. It 1 be noticed that thesolenoid core 47 has" en raised and is'retained in this elevated i po-.sitionby the pawl 55. .Witn the pawl in this position, the switch blade70- is (but of engagement with the contact post66. The raising of thesolenoid core 47 has rocked the lever 59 for moving the valvqflt awayfrom the valve seat 17. With this valve unscated, water is allowed toHow from the pipe 5 through the nip les'8 10 into the pipe 15, by way oft e coupler 11, and the water is then fed tothe compressor. The waterpressure in the coupler 11 will flex the diaphragm 26, forcing, upwardlyupon the same, and the stern 30 will be elevated. The compression spring97, carried bythe stem 30, will operate upon the arm 91 for rotating therod 79. Rotation of this rod 79 will move the' various brushes 87,carried by the blades 86, into -tratcd in Fig. 3, halfway between thecontacts 104 and 107. After the refrigerating l9 -plant has beenoperated for bringing the refrigerator space down to the desiredtemperature, tl1e'thern1ostatic bar 101 will be flexed to the left andwill engage the contact 107. When these elements, 101 and 107, areconnected, a shunt circuit will be established from the main feed lineA, through the wires 11!) and 102 to the the'rmostatic bar 101. Thecontact 107 wi ll be connected by the wire 108 to the n1a rletic coil 52which in turn will be connectell, by the wire 11 1, the binding screw74, the contact plate 7 5, the brush 87, the switch blade 86, and thepigtail 99 to the main feed line C. Current will flow through thiscircuit 'for energizing the magnetic coil 52'and the magnetic fluxcreated thereby will attract the pawl 55 for disengaging the same fromthe bloele 49 carried by the solenoid stein -18. The solenoid will thenbe permitted to drop and upward pressure upon the end 61 of the lever 59will cease. The valve stem 23 and the valve 24 will then move upwardly,due to the pressure of water against the valve 24, and the supply ofwater from the pipe 5 will be cut off,- thereby preventing the flow ofwater to the coinpressor. As the water passes out of the coupler 11, thepressure employedfor retaining the diaphragm 26 flexed upwardly willcease and the stem 80 will be; allowed to drop, due to the pressure ofthe spring 81. Downward movement of this stem 30 will cause the nut 94;to engage the bifurcated end 92 of the arm 90 and the rod 7 will becaused to rotate. This rotary movement o't-the rod 79 will cause all ofthe brushes 87 to be moved out of engagement with the contact plates 75and current will cease to flow throughthe motor t'ced lines (.2 i)- andc for stopping the motor employed for driving the compressor.

It will now be noted that the solenoid core 47 has dropped and that thenormal diameter-oi"? the block 49 carried by the core stem 18 will havemoved the pawl 55 a suliicicnt distance for causing the switch blade toengage the contact post 66. The blades 86 and 70 are'now all in thepositions illustrated in dotted lines in After the temperature rises inthe refrigerator space, the thermostatic bar 101 will be flexed untilitengages the contact 104 whercu on a circuit will be established from t9 mainfeed line A, through the -wire 115 to the post 103 and through thewire 102 to the thermostatic bar 101. Carrent will then flow from thisbar 101 to the contact 104 and through the wires 105 and 1.10 to oneleadof the solenoid coil 10: The second lead of this solenoid coil willbe connected by the wire 111 to the binding screw 71 and theswitch blade70, illustrated in dotted lines, will engage. the contact post 60 forcausing the current to flow through the wire 112 to the main feed lineC. It will now be seen that the solenoid coil .46 will be energized andthat the solenoid core 17 will rise for permitting the pawl 55 to engagethe notch 50 formed in the block -19. The rising of this core 47 willelevate the.

end 61 of the lever 59 and thereby will force the valve 24 oil of theseat 17. The unseating of this valve will permit water to flow to thecompressor. The water pressure in the coupler 11 will cause thediaphragm 26 to be tiered upwardly for operating the stem 30 and the rod75). Rotation of this rod 79 will cause the switch blades 86 to move forplacing the brushes 87 into electrical engagement with the plate 75whereupon current will again be applied to the compressor motor.

It is to be understood, while the water is flowingfrom the supply pipe 5to the compressor tee/ding" pipe 15, the water pressure will vary in thecoupler: 11. pressure increase, the stem 30 will, of course, be movedupwardly a greater dis tance, but due to the spring connection 97between this stem and the arm 91 and the Springs 84 between the arms 81and the switch blades 86, the rod 70 will be permitted to rotate afterthe brushes 87 have been placed into cngagcmcntwith the contact plates79 without causing damage to the blades 80. The diaphragm 20 is intendedto bc influenced by the water pressure witliin the coupler 11 in such amanner that the three-pole switch will be retained in its circuitclosing position until the water pressure should happen to drop to apredetermined low point, such as one or two pounds pressure, whereuponthe diaphragm will return to its normal position operating the the rod79 for moving the switch blades 86 and brushes 87 into their circuitbrcaking positions. Itwill, therefore, be seen that should the waterpressure drop too low or should the water entirely cease to flow, thecompressor motor will be stopped and the compressor will be preventedfrom operating; without any supply of water.

The valvsS-S has been provided in the compressor feed pipe 15 forcontrolling the amount of water ted to the compressor entirelyindependently of the automatic apparatus previously described.

ll; is now believed that the construction, manner of assembling, andoperation of the Should the I s a -1m,

various elements embodying this invention will be understood from theabove detail description and, therefore, no further explanation isdeemed necessary.

It is tobe understood that the form of the invention herewith shown anddescribed ,is to be taken as a preferred example of the same, and thatvarious changes in the shape, size, and arrangement of parts may beresorted to without departing from the spirit of the invention or thescope of the subjoined claims.

' Having thus described the invention, I claimz- V r 1. In arefrigerating apparatus, the combination with a 'ater circulating systemfor a compressor and an electric wiring system for the, compressormotor, of a valve normall seated by water pressure for controlllng theflow of water through the. circulating system, a lever operativelyconnected to said valve, thermostatically con trolled electro-magneticmeans for operating' said lever for unseating said valve, a pawl forholding said valve unseated, a weight connected to said pawl fornormally holding the latter in a position in readiness to hold saidVillX'G unseated thermostatically controlled electro-nnigneticmeans formov ing said pawl into its inoperative position for permitting the valveto seat, a switch for controlling the How of current throughthe'electric wiring system, a water pressure operated diaphragm in thecirculating system, and means for connecting the switch to saiddiaphragm whereby the latter will close said switch when the valve isunseated and will open said switch when the valve is seated. 2. In arefrigerating apparatus, the combination with a water circulating systemfor a compressor and an electric wiring system for a compressor motor,of a valve normally seatedby water pressure for controlling the flow ofwater through the circulating system, a lever operatively connected tosaid valve, a solenoid coil, a movable core for Said Solenoid engagingsaid'lever for unseating said valve when the coil is energized, .acircuit for the solenoid coil, thermostatic means for closing lhccircuit to the solenoid coil, a pivoted pawl for engaging said core tohold saidvalve unseated, means connected to said-pawl for normallyretaining it in a position for engaging said core, a magnet for movingthe pawl out of engagement with said core for permitting said valve toscat, a circuit for 'said magnet, ihcrnn'istatic means for closing thecircuit to said magnets, a switch for controlling the How oi? currentthrough the electric wiring a water pressure operated dia- 'ihragm inthe circulating system, and means for connecting the switch to saiddiaphragm whereby the latter will close the said switch when the. valveis unseatedand will open said switch when the valve is seated.

3. In a refrigerating apparatus, a water circulating system, a valve inthe circulating system normally closed by the water pressure, a stem forsaid valve, a lever operativelyconnected to said stem, a solenoid coil,a movable core for said coil engaging said lever for opening saidv valvewhen the coil is energized, a pivotal pawl associated with said core andadapted to engage the latter for holding said valve open, meansconnected to said pawl for normally retaining it in a position forengaging said core, a magnet for moving the pawl out of engagementv withthe core for permitting the valve to close, and thermostatic means forcausing said solenoid and magnet to operate independently.

4:. In a refrigerating apparatus, awater circulating system, a valve inthe ci'rculat-v pawl out of engagement with the core for permitting thevalve to close, and thermostatic means for causing said solenoid andmagnet to operate independently.

5. In a refrigerating apparatus, a water circulating system, a valve inthe circulating system normally closed by the water pres sure, a stemfor said valve, a lever operativcly connected to said stem, a solenoidcoil, a wiring circuit for said coil, a movable core for said coilengaging said lever for opening said valve when the coil is energized,means for holding said valve open, means operatively connected to saidlast mentioned means for breaking the circuit to said solenoid coilafter the holding means has moved into its operative position, and meansfor moving the valve holding means into its inoperative position forpermitting the valve to close.

6. In a refrigerating apparatus, a water circulating system, a valve' inthe circulating system, normally closed by the waterpressure, a stem forsaid valve, a lever operatively connected to said stem, a solenoid coil,a wiring circuit for said coil,'a movable core [or said coil engagingsaid lever for opening the valve when the core is energized, a pawl forholding said valve open, a switch opcratively-connected to said pawl forbreaking the circuit to said solenoid coil after the pawl has been movedinto its operative position, and electric means for moving the valveholding pawl into its inoperatlve position for permitting the valve toclose.

7. In a refrigerating ap 'iaratus, a Water circulating system for acompressor, a wiring system for a compressor motor, a switch for thewiring system, a pressure operated diaphragm in the circulating system,a stem carried by said diaphragm, an arm carried by said switch, andmeans for connecting the diaphragm stem to the switch arm in such amanner that the switch will be closed when the pressure in thecirculating system rises above a predetermined point and the switch willbe opened when the pressure drops below said predetermined point, saidconnection between the diaphragm stem and the switch arm permitting"circulating system for a compressor, a. wiring system for a compressormotor, a switch for the wiring system, a pressure operated diaphragm inthe circulating system, a stem -arried by said diaphragm, an arm havinga bifurcated end carried by said switch with the diaphragm stem locatedbetween the flu-cations of said arm, and resilient means carried by saidstem and engaging the bifurcated end of said arm whereby the switch willbe closed when the pressure in the circulating system rises above apredetermined point and the switch will be opened when the pressuredrops below said predetermined point, the resilient means permittingmovement of the stem after the switch is closed, due to increase inpressure .upon the diaphragm, without influencing the switch.

In testimony whereof I afiix my signature.

CHARLES SCHXVEINLE,

